Google Cloud Create Local SSD Disks for VMs

Step-01: Introduction¶

What is a Local SSD Disk ?
Implement a demo with Local SSD Disk
Persistent Disk vs Local SSD

Step-02: Create new VM Instance¶

Verify OS COMPATABILITY FOR BEST PERFORMANCE
Go to Compute Engine -> VM Instances -> CREATE INSTANCE
Name: demo9-vm-localssd
Region: us-central
Zone: us-central1-a
Machine family: GENERAL-PURPOSE
Series: N2 (NOT ALL Machine SERIES SUPPORT Local SSDs)
Machine type: n2-standard-2
Boot Disk
- Operating System: Debian
- Version: Debian/GNU Linux 9 (Stretch) - VERIFY OS COMPATABILITY MATRIX
- Boot disk type: Balanced persistent disk
- Size: 10 GB
REST ALL LEAVE TO DEFAULTS
Click on ADVANCED OPTIONS
Clcik on Disks
Click on ADD LOCAL SSD

Finally click on CREATE to create VM Instance

# Create VM Instance with local-ssd disk
gcloud compute instances create demo9-vm-localssd \
    --project=gcplearn9 \
    --zone=us-central1-a \
    --machine-type=n2-standard-2 \
    --network-interface=subnet=default \
    --local-ssd-recovery-timeout=1 \
    --tags=http-server \
    --local-ssd=interface=NVME

Step-03: Mount local SSD Block Device in VM Instance¶

# Verify local SSD disk in VM Instance Properties 
Goto -> Compute Engine -> VM Instances -> Clcik on "demo9-vm-localssd"
Verify "Local disks" 

# Connect to VM instance using cloud shell 
gcloud compute ssh --zone "us-central1-a" "demo9-vm-localssd" --project "gcplearn9"

# Display information about Block Devices
sudo lsblk

# Format local ssd with an ext4 file system
sudo mkfs.ext4 -F /dev/[SSD_NAME]
sudo mkfs.ext4 -F /dev/nvme0n1

# Create Directory to mount the local ssd device
sudo mkdir -p /mnt/disks/disk1ssd

# Mount local ssd on the VM instance
sudo mount /dev/[SSD_NAME] /mnt/disks/[MNT_DIR]
sudo mount /dev/nvme0n1 /mnt/disks/disk1ssd

# Enable Read and Write access to the device
sudo chmod a+w /mnt/disks/[MNT_DIR]
sudo chmod a+w /mnt/disks/disk1ssd

# Verify File system
sudo df -h

##### SAMPLE OUTPUT ######
dkalyanreddy@demo9-vm-localssd:~$ sudo df -h
Filesystem      Size  Used Avail Use% Mounted on
udev            3.9G     0  3.9G   0% /dev
tmpfs           796M  448K  796M   1% /run
/dev/sda1       9.7G  2.0G  7.2G  22% /
tmpfs           3.9G     0  3.9G   0% /dev/shm
tmpfs           5.0M     0  5.0M   0% /run/lock
/dev/sda15      124M   12M  113M  10% /boot/efi
tmpfs           796M     0  796M   0% /run/user/1000
/dev/nvme0n1    369G   28K  350G   1% /mnt/disks/disk1ssd
dkalyanreddy@demo9-vm-localssd:~$

Step-04: Automatically Mount the Block Device when Instance Reboots¶

# Connect to VM instance using cloud shell 
gcloud compute ssh --zone "us-central1-a" "demo9-vm-localssd" --project "gcplearn9"

# Automatically mount the Block Device when Instance Reboots
## Backup /etc/fstab
sudo cp /etc/fstab /etc/fstab_backup_before_localssd

## List UUID of Block Device
sudo blkid -s UUID
Take UUID of "/dev/nvme0n1:" and replace in below command

## Update the /etc/fstab
echo UUID=fd6b5842-ac95-4a93-a215-0a24967f606b /mnt/disks/disk1ssd ext4 discard,defaults,nofail 0 2 | sudo tee -a /etc/fstab

## Verify /etc/fstab
cat /etc/fstab

Step-05: Verify Local SSD¶

# Create a file in local ssd
sudo echo "Welcome to Stacksimplify - VM Hostname: $(hostname) VM IP Address: $(hostname -I)" | sudo tee /mnt/disks/disk1ssd/localssd.html

# Verify File
cat /mnt/disks/disk1ssd/localssd.html

Step-06: Verify Local SSD after system reboot¶

# Verify Uptime before reboot
uptime

# Run Command
sudo reboot

# Connect to VM instance using cloud shell 
gcloud compute ssh --zone "us-central1-a" "demo9-vm-localssd" --project "gcplearn9"

# Verify VM Uptime after reboot
uptime

# Verify Disk
df -h
ls -lrt /mnt/disks/disk1ssd/
cat /mnt/disks/disk1ssd/localssd.html
exit

Step-07: Stop or Delete VM to avoid charges¶

# Stop VM Instance
gcloud compute instances stop demo9-vm-localssd --zone=us-central1-a
gcloud compute instances list --filter='name:demo9-vm-localssd'

Note-1: If a VM has any attached Local SSD disks, you must use the --discard-local-ssd flag to indicate whether or not the Local SSD data should be discarded. 
Note-2: TO PRESERVE LOCAL SSD: To stop the VM and preserve the Local SSD data when
you stop the VM by setting --discard-local-ssd=False.
Note-3: TO DISCARD LOCAL SSD: To stop the VM and discard the Local SSD data, specify     --discard-local-ssd=True.
Note-4: Preserving the Local SSD disk data incurs costs and is subject to limitations

# Delete VM 
gcloud compute instances delete demo9-vm-localssd --zone=us-central1-a
gcloud compute instances list --filter='name:demo9-vm-localssd'

Step-08: Persistent Disk vs Local SSD¶

Understand more about Persistent Disk vs Local SSD
Refer presentation slides for the same.